


Fibonacci Clock

by samworth



Category: Numb3rs
Genre: Birthday Present, Chocolate Box Exchange, Chocolate Box Exchange 2020, Chocolate Box Treat, Family, Fibonacci sequence, Gen, Golden Rectangle, Slice of Life, Treat
Language: English
Status: Completed
Published: 2020-02-14
Updated: 2020-02-14
Packaged: 2021-02-28 07:27:25
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,354
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22709983
Author URL: https://archiveofourown.org/users/samworth/pseuds/samworth
Summary: As neither Megan nor Larry could help Don to find a present for his brother, he had to turn to the one thing that he had no clue of but Charlie loved - math.
Relationships: Charlie Eppes/Amita Ramanujan, Larry Fleinhardt/Megan Reeves
Comments: 8
Kudos: 24
Collections: Chocolate Box - Round 5





	Fibonacci Clock

**Author's Note:**

  * For [kalirush](https://archiveofourown.org/users/kalirush/gifts).



"What are you doing?"  
  
Larry startled and jumped away from the book shelf, jerking his hand back as if he had touched a hot stove. Taking a deep breath to calm his nerves, Larry turned to the door to face his fate.  
  
"Well?" Don asked with a smirk on his face. Megan stood right behind him, never bothering to hide her smile.  
  
But Charlie was nowhere to be seen. The worst outcome had been prevented, and Larry relaxed even if the sight of Megan threatened his focus and flooded his blood with unusual emotions. He forced his mind back to his task. "I am looking for one of my books."  
  
"In Charlie's office?" Megan raised an eyebrow and folded her hands behind her back. Stalking into the room, she kept on smiling. She knew after all Larry and Charlie.  
  
"Well, I know for a certainty that he enjoys and uses my copy of R.A. Fisher's 'Statistical Methods for Research Workers' far more than I do therefore it would be my pleasure to give it to him as a gift for his birthday." Larry dried his palms on his shirt before he edged back to the shelf to keep looking for his prize. "I assume you are looking for Charlie?" he asked.  
  
The agents' expressions changed. While now Don was looking sore, Megan smirked. "Charlie's birthday. I wonder what his brother his getting him if you gift him with a book," she said.  
  
Don growled. "Remind me to never ask you again."  
  
With a mask of pure innocent, Megan turned to Don. "Well, you didn't ask me," she said sweetly. "I just accidentally overheard your conversation with your father." She grinned while Don sighed deeply.  
  
"Oh, the old dilemma - what possession to acquire to give somebody who has all he needs," Larry mused while his finger skimmed along the book spines, each one a treasure of immeasurable worth, if you thought about the content. With a shout of delight, he grabbed the original print version of 'Statistical Methods for Research Workers' and pulled it out.  
  
"Yeah, well, I don't have a book that Charlie likes or wants," Don said and rubbed at his neck. "But I'm still supposed to get him something."  
  
"You know, Don," Larry said as he went by, "you cannot buy a scientist what he desires the most - knowledge." He clapped Don's shoulder who snorted. "But you can buy him a telescope, so he may attain more knowledge himself."  
  
Don coughed and shook his head. "Helpful, Larry, really helpful. Somehow I don't think they sell supercomputers at the next corner store. And if they did, I sure can't afford them."  
  
Megan just laughed. "Larry," she said while she stepped up to him, her shoulder brushing against him. "Where is Charlie? Because we are looking for him and not a book thief."  
  
Larry stopped to enjoy the slight touch and inhaled her perfume. Then he remembered his audience and straightened. "He is borrowing my time with the supercomputer." He grabbed a bag from the chair and let the book slip in. "But he should be soon back."  
  
Don buried his hands in his pockets. "So, you traded time with the supercomputer for the chance to take back a book you want to give him anyhow. Why not just tell him to keep it?"  
  
Larry tilted his head as if he hadn't thought about it like that. Before he could answer, Megan came to his rescue. "One, he donated his precious time on the supercomputer for our case." She offered Larry one of her brightest smiles. "And two," she continued, now shooting Don a smirk, "at least he has a present."  
  
"Yes, yes." Don raised his hands in surrender. "But I'd like to see you shopping for a present for Charlie. It's not as easy as it sounds."  
  
"Well, I'm glad that I have solved this problem for today." Larry held the bag with the book in his arms and pressed it against his chest. "And with that I'll have to bid you goodbye to hide my gift in a secure location," he said and hurried out.  
  
"Not the house, Larry," Don called after him. "There's no safe place in there where Charlie won't find it. I know that."  
  
Megan laughed out loud. "Somehow, I think there's an interesting story behind this sentence."  
  
"You have no idea." Shaking his head, Don sat down at his brother's desk. "But that doesn't help me at all."  
  
"You know," Megan said half leaning against and half sitting on the desk, "I have the same problem. My sisters have everything money can buy, and they don't need my self-baked cookies." Don made a face as if he tried to imagine himself baking Charlie cookies. "But it is a great pleasure to make somebody happy, so I'll buy things they can give away or donate to charity in their names."  
  
Don leaned back, crossing his arms. His lips pursed as he thought about it. "You mean that I don't need to think about getting something for Charlie but getting Charlie something he can use for others?"  
  
"I had thought more along the lines asking him what charity he likes to support," Megan agreed while pushing away from the desk. "But your idea could work, too."  
  
Before they could continue their discussion, a commotion from the door interrupted them. Charlie rushed in with Amita hot on his heels. "Oh, hi Megan. Don." He took a deep breath. "We got a location."  
  
Without spending further thoughts on a gift, Don jumped up and into the case. Megan shrugged and followed his lead. She didn't need a gift for Charlie after all.  
  


* * *

  
"What's that?" Charlie inspected the present still wrapped in silver paper. He was standing next to the couch where Don had sat down right after he had arrived and delivered his package. Alan had claimed his recliner and settled down for a nice and relaxing evening with his sons, while Amita drifted in from the dining room. An anticipating smile already fixed on her face.  
  
"Your gift," Don answered and leaned back in his place. His grin still buried beneath layers of exhaustion. But the first cracks appeared, and he was able to relax his tense shoulders.  
  
"It's small," Charlie noted and eyed the present with narrowed eyes. Mistrusting, he started to shake it a little.  
  
"It's not the size that matters," Don countered with closed eyes as if he wanted to rest a minute. "And it's not ticking."  
  
Charlie sighed. "Did you buy it alone or had you help?"  
  
Don snapped his eyes open, leaned forward and chuckled, his laughter lines replacing the air of exhaustion surrounding him. "Yes, I had help." Somehow he found his brother's worry about what kind of gift he was getting amusing.  
  
"Colby?" Charlie started with the biggest threat. "Or David?"  
  
"Charlie, just open your present. I'm sure your brother didn't buy you something that he also wouldn't want to get himself," Alan ordered. Out of the corner of his eyes he sent his older son a warning glare.  
  
"I do not disclose my source or partner in crime." Don said. He waited until Charlie had looked back down to shoot Amita a conspirative glance. She ducked away to hide her grin.  
  
"Do you want a piece of cake?" Charlie asked to win time without realizing that he had missed an important exchange. He pointed to the dinner table where the last crumbs of a once impressive cake stood. "Dad wanted to keep one for you."  
  
Don just raised an eyebrow.  
  
"Right," Charlie murmured. With a soft thud as if the box was made out of wood, Charlie put down his gift on the small couch table next to a book that Don recognized as Larry's book. Apparently, Megan had successfully reminded Larry, and they had already been by. After the day they had at the FBI, Megan had needed Larry and had planned to use her wildcard.  
  
"You're deflecting." Don stretched until he found a more comfortable resting place. "What's the matter Chuck? Afraid?"  
  
"No," Charlie denied while he grabbed a plate to serve Don his cake. "It's just highly unusual and I ought to be worried about behavior outside of normal parameters." He went over to Don and handed him his plate.  
  
"Uuuhh, uuh! Remind me to never get you a present again." Despite his gripes, Don accepted the cake with a smile and dug in.  
  
"You normally don't get me one." Charlie sat down on the edge of the chair, right next to the presents on the table, his focus already back on it. He simply couldn't let an enigma go unsolved.  
  
Don barely managed to swallow before opening his mouth to answer with a short: "Because I don't know what to get you." He still received a disapproving glare from their father.  
  
"And you also usually don't come over either." Charlie inspected the present from all sides.  
  
Alan cleared his throat while he crossed his legs, leaning back. "Well, one thing has probably something to do with the other thing, hasn't it?"  
  
Don shrugged. His shoulders almost touched his chin, hiding the insecure smile behind a fake grin. Nobody would have been surprised if he had pleaded the fifth. But then he recovered his poker face and straightened up. "But this year, I managed to come by."  
  
"And I appreciate it, even if you look like a zombie."  
  
"Hey, just because I'm a little tired doesn't mean that I won't be able to stay awake until you have opened your present."  
  
"Fine." Charlie hesitated a moment, but then he grabbed the box and tore off the blue wrapping paper in one frenzy move. He blinked and stared at the wooden box in his hands. It was a simple cuboid with smooth edges and a front with five differently sized squares. A few squares were lighted in different colors. Charlie started at the box, trying to figure out what this was.  
  
"It's a clock." Don answered the unvoiced question.  
  
"A clock? Without any hands or numbers?"  
  
"It's a math clock," Don repeated, standing to his answer.  
  
Charlie refrained from repeating his question again, instead he leveled a glare at his brother. Alan stared at the box with raised eyebrows. Amita walked over to her boyfriend. "Really, Charlie, it's a clock for mathematicians."  
  
"There is no such thing." Charlie shook his head missing that Amita knew something that she shouldn't have known. "A clock is a clock. It's something to measure the passage of time. There's no math version of it and this isn't a clock."  
  
"Just because you can't read it, doesn't mean it isn't one." Don grinned while Charlie glared first at the box and then at his brother.  
  
"This is great," Don said and held up his plate but the double meaning was clearly visible.  
  
The biggest square filling half of the front was red lighted. Next to the big square, there were two small squares, each one only a fifth of the big square. One shone blue, the other one green. Filling the bottom left corner, the second biggest square was also red lighted. Most of the front shone red and only two small areas were lighted blue or green. The square in top left corner formed an exception as it wasn't lighted at all.  
  
"Then what time is it?"  
  
"Ten after nine."  
  
"Really?" Charlie voiced his doubts while he checked his watch. The verification of the time elicited a small frown from the math professor.  
  
Amita chuckled. "Yes, really."  
  
Charlie whirled around and glared at his girlfriend." So, you're in this? You are his helper? Are you sure that you're on my side."  
  
"Charlie! Of course, I am on your side." She rubbed along his left shoulder and arm. "I was just a consultant in this case." She kissed his temple.  
  
"To check the math," Don clarified. "I couldn't get you something that's not working."  
  
Suddenly, Charlie seemed to allow the possibility that this was really a clock. "But you can tell the time."  
  
"Yes, this kind of math even I can do."  
  
"All right, let's see if you're right." Charlie grabbed his laptop.  
  
"Charlie, don't!" Amita put her hand on the top of the device, preventing Charlie from booting up his laptop. "Don't ruin the surprise. You can figure it out. It's actually pretty easy but fun." She leaned in so near that their noses almost touched.  
  
Charlie narrowed his eyes before he turned his head to eye his father. "Are you in too, Dad?"  
  
"No, my son, I cannot say that," Alan acknowledged the slight accusatory tone of voice. "But I'm surprised that you haven't figured it out yet. Usually, you had all your gifts involving math figured out before we could throw away the wrapping paper. So, we stopped buying you math related items."  
  
Charlie growled. "Fine." He put away the laptop and refocused on the wooden box. "What time is now?" he asked without looking up from his new-found task.  
  
Don took a deep breath. A look of concentration settled on his features until he relaxed again. "Nine twenty."  
  
Consulting his own watch, Charlie started to think. "That's not precise." He looked up to Amita. "It's not precise. What kind of math would that be?"  
  
Amita leaned back and crossed her arms, sighing. "Look at the box. Does the pattern remind you of something?"  
  
"Of course. It's a golden rectangle based on the Fibonacci sequence. One, one, two, three, five." He pointed at all the squares on the front. "I recognized the pattern the moment I saw it. But that's just the design and it wouldn't be something you'd classified as math."  
  
"Right." Amita tilted her head. "So?" she prompted.  
  
"The Fibonacci sequence is everywhere - in nature, in cosmology and ..." Charlie trailed off, his fingers absently stroking his jaw. Suddenly, he paused, straightening. "And you can create all numbers from one to twelve with just the first five numbers." He glanced at the window without seeing outside, his focus entirely on the math in his head. "And that's all you need to display a time. It's not a clock but a time display!" he shouted in triumph and pointed at Don. "Not a clock."  
  
Don threw up his hands. "A clock is a clock."  
  
"Not if it's only a way to show the time but cannot determine the passage of time. But let me see ..." Charlie grabbed a pen and paper. "We have three colors - red, green and blue." He started to scribble down some numbers while Amita offered Don a consoling smile.  
  
"No, that doesn't work," Charlie murmured. "What time does it show now?" he asked as the lights changed again.  
  
Don sighed but dutifully calculated it. "Nine twenty-five." Then he closed his eyes and rubbed circles along his temples.  
  
Charlie scribbled again on his notepad. "All right, it only gives you minutes in multiples of five. That of course is necessary to get sixty minutes." He paused, chewing his pencil. "Give me five to figure out how it displays the time." He looked up to Amita. "It's working, right?"  
  
"It is. I even checked the source code. It's a sound approach," Amita verified.  
  
"All right." Charlie accepted the answer with a nod. He waited for the lights to change. "Three colors and unlighted as a forth option."  
  
In the end, he didn't even need full five minutes to figure it out. "The only way it could work and display all possible times is if you mix it - one color used for both minutes and hours and then respectively one additional color for minutes or hours."  
  
Amita giggled. "I should have taken the bet."  
  
"What bet?" Charlie glared from Amita to Don and back.  
  
"Do you really have to ask?" Don grumbled. "But it's math. Of course, you are right." He stood up and walked over to his brother. Even Alan rose and shuffled over. Don pointed at the differently lighted areas. "Each square represent a number of the Fibonacci sequence. Sum of red and blue squares is for hours while minutes are calculated by adding the green and blue squares and multiplying it by five."  
  
"You'd only need a circuit board and a few LEDs." He glanced to Amita. "Then it just needs some source code to measure time and light the LEDs to show the time."

Amita nodded.  
  
Turning the box into his hands, Charlie was surprised to find himself liking the way it displayed the time. Then his gaze flickered to the wrapping paper that had been discarded. He had done it again. "I hope I didn't ruin your surprise," Charlie glanced up to his big brother, shifting in place. "It really wasn't hard to figure out and -"  
  
"Charlie!" Don threw his arm around his brother's shoulder. "I have given up trying to challenge you with math. But I need to worry about the next generation."  
  
"Next generation?" Charlie stiffened.  
  
Don lowered his gaze, shrugging. "You like to challenge your students."  
  
Slowly, a smile bloomed on Charlie's face. "You got me this clock for my classroom?"  
  
"I thought," Don said and shrugged again, "that you maybe wanted to use something new." He raised his head, trying to catch his brother's eyes.  
  
The small smile on Charlie's face gave way to a full-blown laugh. "That's -" he searched for the right word but it remained elusive. Pride and satisfaction mixed with pure joy flickered across his face, and he had to settle for a more general, "great." But his voice and expression expressed what his words couldn't get across.  
  
"Yeah, well, after you have retired, the FBI is still going to need math professors for consulting. So it's better to ensure that they at least are capable of spotting a Fibonacci sequence."  
  
Charlie chuckled. "After I retired? You're well on your way to an old people's home before I even have to think about it. Math doesn't age."  
  
"Fair enough, but don't you think you're getting bored without me there?" Don smirked.  
  
"Never. I can't get bored with math. That's not possible. And Colby and David are still going to be there."  
  
Don laughed out loud. But before he could explain his brother the normal career path of an FBI agent that wasn't derailed by a dying mother, Alan intervened. "Boys! No arguing." The admonishment came naturally to Alan. "If you don't watch it, you'll resign at the same time and then you have to found your own private investigation firm." He crossed his arms, warming up to his spontaneous idea.  
  
Don and Charlie stared at their father with open mouths, a little speechless about the idea. Amita didn't have the same restraint and laughed out loud. "That's a great idea. You mean something like Eppes & Eppes?"  
  
The stern mask on Alan's face cracked and a smile played at his lips. "Well, a few years ago I couldn't imagine my boys working together. Now, I can't imagine them not working together. I guess, they are going to find a way to continue working together."  
  
"But not as private investigators!" Don and Charlie said at the same time.  
  
"The cheaters of LA won't stand a chance." Amita's words were almost lost, she giggled so hard.  
  
"This isn't funny." Charlie pouted and crossed his arms. Amita went to Charlie's side, putting her arms around him. "I think it's a fabulous idea. I would even offer to join your firm."  
  
"Besides, you won't even have to argue about who is named first," Alan threw in with a chuckle.  
  
Finally, Charlie cracked and joined the laughter. "But I wanted to be named first. C is before D."  
  
Don shook his head, but he also started to grin at the image. First, he hadn't known what the Fibonacci sequence was. Then math had become the trademark of his brother, out of reach for Don. And now he had recognized and bought his brother a Fibonacci clock himself. Of course, Amita had checked it out for him but still he had willingly bought something math.  
  
Time and people changed - but a brother remained a brother.  
  
**END**

**Author's Note:**

> Update: there really is a Fibonacci clock (https://basbrun.com/2015/05/04/fibonacci-clock/) or you can also use a search engine for some images.


End file.
